Stable anti-corrosive lubricant composition



3. l approximately 250% theoretical barium oxide in water solution for several hours at 160 to 180 F. followed by dehydration by raising'the temperature to 300 F. The product was ltered with Supercel .to obtain a basic EXAMPLE IV The following Table I lists the analyses of fourteen different metal salts of di-Z-ethylhexyl dithiophosphoric acid.

bariumsultonate whichanalyzed as follows TABLE I gellrtolat'glg 4 Y I Ana-lysskof ymetz/1l dz'-2ethyllrexyl dithiophosphates The following Examlles'l-I and In iuustate the Prep' Percent Metall Percent P Percent S lax'atiort of thenickel salt of di-Z-ethylhexyl dithiophos- 10 Metalv l phoricacid using nickel carbonate or nickel oxide of Foood Theory Found Theory pound Theory small crystallite size.

I EXAMPLE II NielflMade from 'Z-ethylhexanol (5200 grams) was placed in a 1 2 lite 15 Bllfgog'f'too'f' 7568 768 8'@ 8'13 20 m78 round bottomed, three-neck ask. A glass agitator an Nico. 6.41 7.24 .6o thermometer were fitted to the flask. The ltemperature 1g: lj gig gj 21 21,8 of the alcohol was increased to 168 F. by heating.' At leb 'this point, phosphorus pentasulde was slowly added to 13:70 13:72 7:56 715g 15110 v15262 the agitated mixture at a constant rate and over a period s (15gg (l-gg -g g-g g 1%781) of 5 hours.r The total amount of phosphorus pentasuliide 8165 9198 96 91V 15120 wr used was 2220 grams. To remove traces of unreacted ggg fig '42(1) g-g '-g ggg products in vthe solution the acid was filtered through l gjg gj 'ulst -uiig aper at room temperature. .Y

354 grams ofthe di2 ethylhexyl dithiophosphoric acid 25 7'52' 7'71 8'10 8'14 16" 60 16.18 thus obtained were then placed in a l'liter three-necl tlask'f To the acid were added 300 grams toluene an l'0grams water. The temperature was increased to 160- EXAMPLE v v 'l 200 P. and 60 g. nickel carbonate (ous) was slowly The followingTable II lists the results of laboratory added.l As the nickel carbonate was added the solution oxidation tests jrun on oil blends including 27% of basic 'became'. Purple in C OlOr- -After about 5:110111S-16a6ti01'1 mahogany sulfonate concentrate containing about 'time the material was filtered through Hy-Flow ilter aid 13%' sul'fonate preparedje'ssentially as in Example I. and'paper.y To remove solvent toluene; .the salt solu- Each of the fourteen metal ydithiophosphates shown in -tionwas stripped at a temperature'of 170 F. and1015 Table I were blended 5to a. common phosphorus level of mm. Hg. The yield of nickel salt formed, calculated in v0.094% in a 95 VJ. 160 SUS vis/ 100 F. Mid-Continent weight of acid used was 95%. neutral base'. 'Ihe oxidation test consisted of bubbling 5 liters of oxygen per hour through 300 grains of oil blend at 285 F. in the presence of aV copper-lead catalyst Analysts of sample for v144 hours for analysis. 60 lgram samples of oil were 10 taken YIat 48, 96 and 144 hours. After each sampling Found Percent 7 68 l Low Ni, S, P, believed to be due to the presence of some solvent.

EXAMPLE Il] "neck ask. To the acid were added 200 grams toluene and 7grams water. The temperature of the mixture was increased to 160 F. y* At this point, 40 grams of NiO were added.

The oxide used was 71% nickel and it had 40 to 60 A. crystallite size (as determined by X-ray methods). After Y about 7 hours at `160-170 F., the dark purple solution was ltered through Hy-Flow lter aid and paper. The 'toluene was removed from the filtered solution by stripping to a pot temperature of 170 F. and 10-15 Hg pressure. The yield of nickel salt formed, calculated on weight of acid used, was 92%. Y

Analysis of Sample `.Sinon60160;1.0781 E; 7.5

except the last, v grams of fresh oil were added as lmake-up. The results shown in TableII below are from the V144 hour samples. Except where indicated, a1lthe metal salts were obtained from the di-2-ethylhexyl dithiophosphates prepared essentially as in Example II. It will readily be seen from' the results of the severe oxidation test in "Iable H that the additive combination of the present invention easily gave the best results. The nickel salts of dithiophosphoric acid diesters formed the least sludge or varnish, Acontainedthe least pentaneinsolubles, gave the least viscosity rise and eiected the lowest copper-lead-catalystloss'. As also shown, the nickel dithiophosphate preparedv from nickel carbonate performed better thanthat prepared from -nickel oxide.A

VThe silver corrosionjnhibiting propertiesof the lubrieating oil composition prepared from the additives described inl Examples -II andIII andthe basic barium sulfonate andv base oil of `Example V were determined .bystirringn a sample of oil for 72 hours in the presence v of silver and copper test specimens, after which the silver specimen was cleaned with aKCN solution and' itsweight changedetermined. This test was run at both 285 F. and 325 F. although the former temperature is most commonly used.

In thistest, the oili blendsV containing the nickel-di-Z- ethylhexyl dithiophosphate allowed the lowestloss in weight of the silver at 285 F.,'and gave good results at V325 F. This indicates that these oils, adjusted in viscosity, have less tendency to corrode silver bearings, such as those commonly found in railroad, submarine and certain other internal combustion engines, whereasmany yof the other -oils tested would' prove too corrosive.. :Ex- @cept indicatedall.the metall salts wereprepared from TABLE II y `Oxidation tests Y .viseoiity,.1ereeetf i 12955111 e. H. 1,., Rise at` Fontane Acid'.kv Cu-Pfb @l/.fetal l)ltliiophoslphatesI/ 100"F:,A Insol- Number Catalyst 'Appearance oi Tube ,Y ,Y ,SUSY l u-bles g, Wt."k

23.7 0.251 5.93 23.3 lightwsludgemndyarnish.

Le; 3 ,orme 1.69 28.2 No sludge or varnish. Y 13.2 0.013 3. 54 0.2 D0. .3g 0,050.; 1.532 p 0.3 Slightludge andVarnlsh. 127.2 4.9 z 'ma 6128.4 Heavysludge andvamis'h. 114.4 7.591 13.02 297.0 DO. 150. 8 8. 681 16. 23 447. 9 D0. v142. 1 6.044 17. 13 285. 7 Db. 57. 7 4. 394 7. 94 157.3 D0. 199. 2 4. 868 15. 85 458. 7 DO. 98. 1 8. 485 15. 29 702. 5 D0. 130. 1 9. 415 17. 28 571 D0.

38.5 5.28 5.28 65.1 Mlegilm Heavy Sludge and Var 53. 1 0. 702 2. 33 238. 8 D0. 50. 5 3. 709 5.06 73. 2 Do. 46. 4 10. 953 15.07 467.0 Heavy Sludge and Varnish. 38.6 6.22 8.80 121.2 Mlidsgim Heavy Sludge and Varl Nickel di-methylamyl dithiophosphate, made from methylam l alcohol or 4methylpentanol2. 2 Nickel 11i-tertiary octylphenyl dithiophosphate. y

the d1-2-ethylhexy1 dlthiophosphate prepared essentially EXAMPLE VIII as in Example II.

TABLE III Loss in Wt. of Silver Strip, Mgs. Metal Dithlophosphates 285 F. 325 F. Test Test Nickel:

A Made from NiO 1. 6 12.0 B Made from NiCOg.- 1. 7 2. 6 Zim; 11. 6 15. o Barium 17. 8 54. 5 Calcium 27. 7 37. 6 Magnesium 4. 5 7.1 Cadmium 18. 9 26. 0 Lithium 37, 8 31, 1 Sodium 51. 3 39. 9 Pnta 111m 24. 4 30. 4 Copper 6. 5 4. 0 T 71. 3 16. 4 31. 5 239. 7 177. 8 13. 9 10. 7 18. 0 Nickel L 9. 9

1 Derived from methylamyl alcohol. 2 Derived trom tertiary octyl phenol.

,XEXAMPLE VII A 36-hour L-4 Chevrolet engine'test was also used in evaluating the lubricating composition preparedf in accordance with this invention. In this test the engine is a conventional Chevrolet engine with 216.5 cu. in. piston displacement and a compression ratio of 6.5 to 1. The engine is operated at 3150 r.p.m. with a load of 30 B.H.P. and at a temperature at the jacket outlet of 200 F. The L4 Chevrolet test was carried out on an SAE 10W cil containing 27% basic barium mahogany sulfonate concentrate containing about 13% suifonate prepared essentially as in Example I, nickel di-Z-ethylhexyl dithiophosphate in an amount to provide 0.075% P to the total composition, 1.4% rV.I. improver and 0.005% foam inhibitor, in a 95 V.I. Mid-Continent neutral base. The oil sump temperature was maintained at 265 F. The following results were obtained.

L-4 engine test Mgs. Varnish deposits piston skirts 9.5 Total varnish and sludge 95 Copper-lead bearing loss/whole bearing 38 Results of rocker arm shaft wear tests on oils containbarium mahogany sulfonate are shown in Table IV.v

These 100 hour tests were run in a popular make 1955 V8 engine which is experiencing excessive wear of this portion of the valve train in the field. A smooth contact area on the rocker arm shaft with little or no wear, is highly desirable in this test. A rough wear area accelerates the amount of wear with further running.

As readily seen in Table IV, the results of these tests show that the oils containing the nickel dilthiophosphate and the basic sulfonate gave the smoothest contact areas, about 10 microinches, of the dithiophosphates tested,r with very little or no wear. The original shafts show -25 microinches finish, indicating that the oils containing the nickel dithiophosphate have a mild, polishing action in these areas. The oils containing the other dithiophosphates and the basic sulfonate are unsatisfactory in giving coarse to rough wear areas. The rocker arm shaft wear tests were run on an SAE 10W grade oil containing 27% basic barium mahogany sulfonate concentrate comprising about 13% sulfonate, prepared essentially as in Example I, 1.4% V.I. improver, and various metal dial'kyl dithiophosphates blended to 'a common phosphorus level of 0.12%. In tests 5 to 7 the various runs were carried out on the same reference oil except that 1.25% of sulfur-ized sperm oil was added as an anti-wear agent. Similarly, the lubricating compositions of this invention may contain other lubricating oil additive agents such as detergents, dyes, pour depressors, viscosity index improvers, defoamers and the` like, which are designed to impart desired characteristics to the mineral oil.

TABLE Iv l Rocker arm shaft wear tests f7 I claim: i

1. A lubricating oil composition consisting essentially of a major proportion of mineral lubricating oil and minor amounts of an oil-solublenickel.dithophesphate diester in which each organic group contains from about 4 to 14 carbon atoms, and a basic barium mahogany sulfonate formed by neutralizing a mahogany sulfonic acid with at least -about 1.5 equivalents of a basic barium compound and wherein the barium lcontent is from about 0.2Y Y- from about 0.03 to 0.3 percent by Weight based on thek ,fr f 5 total weight of said composition.

to 2.0 percent by weight and the phosphorus content is oil -is a solvent-treated Mid-Continent oil.

3. The composition of claim 1 wherein said dithiophosphate is nickel di-Z-ethylhexyl dithiophosphaite.

2. Thecomposition of claim 1 wherein the minerald."V` j j 696,064;j

UNIIln-ED STATES PATENTS 

1. A LUBRICATING OIL COMPOSITION CONSISTING ESSENTIALLY OF A MAJOR PROPORTION OF MINERAL LUBRICATING OIL AND MINOR AMOUNTS OF AN OIL-SOLUBLE NICKEL DITHIOPHOSPHATE DIESTER IN WHICH EACH ORGANIC GROUP CONTAINS FROM ABOUT 4 TO 14 CARBON ATOMS, AND A BASIC BARIUM MAHOGANY SULFONATE FORMED BY NEUTRALIZING A MAHOGANY SULFONIC ACID WITH AT LEAST ABOUT 1.5 EQUIVALENTS OF A BASIC BARIUM COMPOUND AND WHEREIN THE BARIUM CONTENT IF FROM ABOUT 0.2 TO 2.0 PERCENT BY WEIGHT AND THE PHOSPHROUS CONTENT IS FROM ABOUT 0.03 TO 0.3 PERCENT BY WEIGHT BASED ON THE TOTAL WEIGHT OF SAID COMPOSITION 